diff --git a/.changeset/retrieval-include-document-ids.md b/.changeset/retrieval-include-document-ids.md
new file mode 100644
index 0000000..84204e9
--- /dev/null
+++ b/.changeset/retrieval-include-document-ids.md
@@ -0,0 +1,5 @@
+---
+"@ontos-ai/knowhere-sdk": minor
+---
+
+Add `includeDocumentIds` to retrieval queries so callers can restrict one request to an explicit document set. Empty arrays are preserved on the wire; omitted means unrestricted; exclusions still win.
diff --git a/README.md b/README.md
index b30a13a..b981054 100644
--- a/README.md
+++ b/README.md
@@ -515,12 +515,17 @@ without creating SDK local-disk cache state. Use `syncParsedDocument(...)` to
 explicitly resume or retry parsed-storage sync for an existing `documentId`,
 `jobId`, or local parsed result.
 
-Follow-up queries can exclude documents or sections for one request:
+Retrieval queries can limit documents and exclude documents or sections for one request.
+`includeDocumentIds?: string[]` restricts retrieval to the supplied document IDs.
+Omitting it leaves documents unrestricted by inclusion; passing `[]` matches no
+documents. Exclusions take precedence over inclusions, including when a document
+ID appears in both `includeDocumentIds` and `excludeDocumentIds`.
 
 ```typescript
 const followUp = await client.retrieval.query({
   namespace: 'support-center',
   query: 'battery charging',
+  includeDocumentIds: ['doc_123', 'doc_old'],
   excludeDocumentIds: ['doc_old'],
   excludeSections: [{ documentId: 'doc_123', sectionPath: 'Appendix / Legal' }],
 });
diff --git a/src/resources/__tests__/retrieval-wire.test.ts b/src/resources/__tests__/retrieval-wire.test.ts
new file mode 100644
index 0000000..54aa7b6
--- /dev/null
+++ b/src/resources/__tests__/retrieval-wire.test.ts
@@ -0,0 +1,83 @@
+import { createServer } from 'node:http';
+import { once } from 'node:events';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { Knowhere, type RetrievalQueryParams } from '../../index.js';
+
+describe.each(['apiKey', 'authTokenProvider'] as const)('Retrieval wire payload (%s)', (auth) => {
+  beforeEach(() => {
+    vi.stubEnv('KNOWHERE_API_KEY', '');
+  });
+
+  afterEach(() => {
+    vi.unstubAllEnvs();
+  });
+
+  it.each<{ name: string; params: RetrievalQueryParams; body: string }>([
+    {
+      name: 'includes overlapping include/exclude IDs and section exclusions',
+      params: {
+        query: 'battery charging',
+        includeDocumentIds: ['doc_123', 'doc_old'],
+        excludeDocumentIds: ['doc_old'],
+        excludeSections: [{ documentId: 'doc_123', sectionPath: 'Appendix / Legal' }],
+      },
+      body: '{"query":"battery charging","include_document_ids":["doc_123","doc_old"],"exclude_document_ids":["doc_old"],"exclude_sections":[{"document_id":"doc_123","section_path":"Appendix / Legal"}]}',
+    },
+    {
+      name: 'preserves empty inclusion and exclusion arrays',
+      params: { query: 'battery charging', includeDocumentIds: [], excludeDocumentIds: [] },
+      body: '{"query":"battery charging","include_document_ids":[],"exclude_document_ids":[]}',
+    },
+    {
+      name: 'omits document filters when not supplied',
+      params: { query: 'battery charging' },
+      body: '{"query":"battery charging"}',
+    },
+  ])('$name', async ({ params, body }) => {
+    let receivedBody = '';
+    let receivedMethod: string | undefined;
+    let receivedUrl: string | undefined;
+    let receivedAuthorization: string | undefined;
+    const server = createServer((request, response) => {
+      receivedMethod = request.method;
+      receivedUrl = request.url;
+      receivedAuthorization = request.headers.authorization;
+      request.setEncoding('utf8');
+      request.on('data', (chunk: string) => {
+        receivedBody += chunk;
+      });
+      request.on('end', () => {
+        response.writeHead(200, { 'Content-Type': 'application/json' });
+        response.end('{"results":[]}');
+      });
+    });
+
+    try {
+      server.listen(0, '127.0.0.1');
+      await once(server, 'listening');
+      const address = server.address();
+      if (!address || typeof address === 'string') throw new Error('Expected TCP server address');
+      const client = new Knowhere({
+        baseURL: `http://127.0.0.1:${address.port}`,
+        ...(auth === 'apiKey'
+          ? { apiKey: 'test-key' }
+          : { authTokenProvider: (): string => 'test-token' }),
+        maxRetries: 0,
+      });
+
+      await client.retrieval.query(params);
+
+      expect(receivedMethod).toBe('POST');
+      expect(receivedUrl).toBe('/v2/retrieval/query');
+      expect(receivedAuthorization).toBe(
+        auth === 'apiKey' ? 'Bearer test-key' : 'Bearer test-token',
+      );
+      expect(receivedBody).toBe(body);
+    } finally {
+      await new Promise<void>((resolve, reject) => {
+        server.close((error) => (error ? reject(error) : resolve()));
+        server.closeAllConnections();
+      });
+    }
+  });
+});
diff --git a/src/resources/__tests__/retrieval.test.ts b/src/resources/__tests__/retrieval.test.ts
index cf10fbb..60ce4c1 100644
--- a/src/resources/__tests__/retrieval.test.ts
+++ b/src/resources/__tests__/retrieval.test.ts
@@ -50,6 +50,7 @@ describe('Retrieval Resource', () => {
       rerank: true,
       threshold: 0.2,
       internalRecallK: 25,
+      includeDocumentIds: ['doc-123', 'doc-old'],
       excludeDocumentIds: ['doc-old'],
       excludeSections: [
         {
@@ -72,6 +73,7 @@ describe('Retrieval Resource', () => {
       rerank: true,
       threshold: 0.2,
       internalRecallK: 25,
+      includeDocumentIds: ['doc-123', 'doc-old'],
       excludeDocumentIds: ['doc-old'],
       excludeSections: [
         {
diff --git a/src/types/retrieval.ts b/src/types/retrieval.ts
index 6555254..2038211 100644
--- a/src/types/retrieval.ts
+++ b/src/types/retrieval.ts
@@ -58,7 +58,13 @@ export interface RetrievalQueryParams {
   threshold?: number;
   /** Override the internal per-channel recall count */
   internalRecallK?: number;
-  /** Documents to exclude for this request only */
+  /**
+   * Limit retrieval to these documents for this request only.
+   * Omitted means no document inclusion restriction; [] matches no documents.
+   * Exclusions take precedence over inclusions.
+   */
+  includeDocumentIds?: string[];
+  /** Documents to exclude for this request only, even when included in includeDocumentIds. */
   excludeDocumentIds?: string[];
   /** Document sections to exclude for this request only */
   excludeSections?: RetrievalSectionExclusion[];